In a prior art headrest, a headrest moving device having a tilting structure or a sliding structure is suggested wherein the gap between the headrest and the back of the passenger's head can be arbitrarily adjusted by rotating the headrest with respect to the fixed point thereof so as to be slanted for a certain degree while the headrest is being fixed to the backrest.
In a headrest of the prior art adopting a sliding structure or a tilting structure, a plurality of teeth is formed along the lengthwise direction so that the position of the headrest can be adjusted, and the headrest can be automatically returned by providing a return spring as suggested in Korea Patent No. 790535, Korea Utility Model Publication No. 2000-0015501, Korea Patent No. 403478, Korea Patent Publication No. 2007-0105210, and US Patent Publication No. 2011-0221250.
However, such a prior art structure is inconvenient for a user in that since the force for moving the headrest must be increased as the headrest is moving further from the initial position thereof when moving the headrest because the stopping position of the headrest moving device remains the same.